The T5X is a Quiet Drive full-featured five-function DCC decoder with Dither. It has X series features. It has a standard 9-pin JST plug with one extra wire. The best decoder with the most features at this price! It is supplied with our standard wiring harness. Other harnesses with NMRA 8-pin plugs are available. Length: 1.000" x Width: 0.680" x Height: 0.250"